611fbca1c8
Get and enable the peripheral clock required by the efuse device. The driver has been handle to work without it so far because the clock was left enabled by default but it won't be the case soon. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
111 lines
2.8 KiB
C
111 lines
2.8 KiB
C
/*
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* Amlogic Meson GX eFuse Driver
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*
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* Copyright (c) 2016 Endless Computers, Inc.
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* Author: Carlo Caione <carlo@endlessm.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*/
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#include <linux/clk.h>
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#include <linux/module.h>
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#include <linux/nvmem-provider.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/firmware/meson/meson_sm.h>
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static int meson_efuse_read(void *context, unsigned int offset,
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void *val, size_t bytes)
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{
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return meson_sm_call_read((u8 *)val, bytes, SM_EFUSE_READ, offset,
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bytes, 0, 0, 0);
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}
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static int meson_efuse_write(void *context, unsigned int offset,
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void *val, size_t bytes)
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{
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return meson_sm_call_write((u8 *)val, bytes, SM_EFUSE_WRITE, offset,
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bytes, 0, 0, 0);
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}
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static const struct of_device_id meson_efuse_match[] = {
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{ .compatible = "amlogic,meson-gxbb-efuse", },
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{ /* sentinel */ },
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};
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MODULE_DEVICE_TABLE(of, meson_efuse_match);
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static int meson_efuse_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct nvmem_device *nvmem;
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struct nvmem_config *econfig;
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struct clk *clk;
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unsigned int size;
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int ret;
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clk = devm_clk_get(dev, NULL);
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if (IS_ERR(clk)) {
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ret = PTR_ERR(clk);
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if (ret != -EPROBE_DEFER)
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dev_err(dev, "failed to get efuse gate");
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return ret;
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}
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ret = clk_prepare_enable(clk);
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if (ret) {
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dev_err(dev, "failed to enable gate");
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return ret;
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}
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ret = devm_add_action_or_reset(dev,
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(void(*)(void *))clk_disable_unprepare,
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clk);
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if (ret) {
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dev_err(dev, "failed to add disable callback");
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return ret;
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}
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if (meson_sm_call(SM_EFUSE_USER_MAX, &size, 0, 0, 0, 0, 0) < 0) {
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dev_err(dev, "failed to get max user");
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return -EINVAL;
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}
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econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
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if (!econfig)
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return -ENOMEM;
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econfig->dev = dev;
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econfig->name = dev_name(dev);
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econfig->stride = 1;
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econfig->word_size = 1;
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econfig->reg_read = meson_efuse_read;
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econfig->reg_write = meson_efuse_write;
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econfig->size = size;
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nvmem = devm_nvmem_register(&pdev->dev, econfig);
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return PTR_ERR_OR_ZERO(nvmem);
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}
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static struct platform_driver meson_efuse_driver = {
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.probe = meson_efuse_probe,
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.driver = {
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.name = "meson-efuse",
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.of_match_table = meson_efuse_match,
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},
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};
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module_platform_driver(meson_efuse_driver);
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MODULE_AUTHOR("Carlo Caione <carlo@endlessm.com>");
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MODULE_DESCRIPTION("Amlogic Meson GX NVMEM driver");
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MODULE_LICENSE("GPL v2");
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